Answers for "center a div grid bootstrap"

bootstrap center align columns

<!-- Center columns in a Row -->
<div class="row d-flex justify-content-center text-center">
    <div class="col-4">
        // Add Content
    </div>
    <div class="col-4">
        // Add Content
    </div>
    <div class="col-4">
        // Add Content
    </div>
</div>

Center a Column in Bootstrap

How to Center a Column in Bootstrap

Use the mx-auto Class

Example
<div class="container">
    <div class="row">
        <div class="col-sm-6 mx-auto">
            <!-- Column content -->
        </div>
    </div>
</div>